Cards having electronic memory and enabling their holders to perform various transactions are now well known. There are two broad categories of such cards. Some cards have electronic circuits which are sufficiently complex to enable credit data to be reloaded into the card memory. In other words when the initial credit in the card has been spent, the user can have the card 37 reloaded" with a new amount of credit in return for suitable payment. A second or "pre-paid" type of card contains a simpler electronic circuit and the card is loaded once only with a given amount of credit. Once this credit has been spent by the user, the card must be thrown away.
It will be understood that pre-paid cards which can be used once only must be capable of being manufactured as cheaply as possible so that the manufacturing cost of the card is not excessive relative to the necessarily small amount of credit which it is capable of storing. Low cost is achieved in part by the fact that the electronic circuit itself is considerably less expensive than the electronic circuit of a reloadable card. However, the cost of manufacturing the card itself is a non-negligible quantity in the final cost of the card. Such a card is essentially constituted by a body made of plastic material, and an electronic module lodged therein, said module comprising the integrated circuit, contact tabs for providing connection with a card reader, and electrical connections between the integrated circuit and the contact tabs. The electronic module must be fixed in the body of the card in a manner which is capable of ensuring that the resulting assembly can pass the bending tests to which such cards are subjected. In addition, the thickness of the card is standardized, and the standard thickness is about one millimeter. It will be understood that this small thickness increases the difficulty of installing and fixing an electronic module in the card.
In general, the electronic module is made using a printed circuit technique. More precisely, the electronic module comprises an insulating substrate on which conductive tracks are formed to provide a portion of the electrical connections between contact tabs likewise formed on the insulating substrate and the terminals of the semiconductor chip itself. The semiconductor chip is fixed on one of the faces of the insulating substrate and its terminals are connected to the conductive tracks by means of conductive wires, for example. This technique suffers from the drawback that manufacturing printed circuits is relatively expensive if the printed circuit is to be very small with a high density of conductive tracks.
In order to remedy this drawback, one aim of the invention is to provide a method of making electronic memory cards which does not make use of printed circuit techniques for making the electronic module.